Cooling jacket for combustion chambers



IN VENT-0R cooLING JACKET Fon lcomausmon CHAMBERS A Filed sept. 25. 1945 Patented Nov. 4, 1947 UNITED STAT ES Pr-iTEN'Iv OFFICE SUGLI-NG JACK T FOR COMBUSTION CHAMBERS Geoffrey Joseph Gollin, Great Saint Helens, Lon-V don, England, assignor to TheAsiatc Petroleum Company, Limited, London, EnglandI Application September 23, 1943-, SerallN'o; 503,521-

I-n Great Britain December 'i-l, 1942 broughtI into `contact is known. toy be a function of the velocity of ii'ow ofthe fluid relative to that surface. In certain cases the amount of heat which itis desired to removefrom the surface is of such a` high order thatwhen using an ordinary type; of cooling jacket in order toattain a sufficiently high fluid velocity and therefore rate of heat transfer it is necessary either to employ an inordinate amount of fluid or fluid passages having an extraordinary small cross section.

The cooling jacket according to the present invention is designed so that the coolant would pass over the surface or surfaces to be cooled at a far higher speed than that equivalent to the quantity of coolant passing through the jacket and the cross sectional area offered to the flow. Its characteristic feature is that it has an annular passage and an inlet adapted for the admission of coolant at high velocity so as to rotate the body of coolant in the passage at high speed, the cross-sectional area of the annular passage being large in relation to the area of flow from the inlet.

The annular passage may have various forms in cross section according to the purpose and application of its use.

In one form it is substantially triangular in cross-section, the inlet being arranged tangentially at a point corresponding to an apex of the triangle. With this form the cooling surface may be substantially of conical form with the inlet at the apex of the triangular cross-section corresponding to the wider part of the cone.

A restricted outlet for the coolant may be provided and this in the case of the conical form of the cooling surface may be at or near the narrow part of the cone. The outlet may comprise a plurality of orifices in and spaced around a Wall of the jacket. In this case the coolant may be discharged into the space to be cooled, e. g. into a combustion chamber around part of which the cooling jacket is arranged.

In cases where the operation of the furnace or engine is of short duration it is possible, according to the invention, to make the capacity of the jacket such that the coolant present in the jacket has a sufficient heat capacity to absorb heat desired to be taken away from the cooling surface during the time of operation, in which case the fluid passed in and out of the jacket is 2. just adequate toi: maintain the fluid in. the jacketin a state.r of high rotational veloci-ty.

By causing the incoming coolant to enter at a high Velocity, e.r g. through the constriction in the inlet pipe, a very small quantity of coolant:

will suffice to maintain the body of coolant in thee annular jacket at a high rotational velocity. For' instance, in a particular case Water may be inw troduced at a velocity of, say, 100 feet per second, using about twopounds of Water per second,` so

that the momentumof the incoming jet keepsth-el.

water in the jacket rotating at a speed of, say, 30 feet per second. If such an amount of water were passed into the annulus through an inlet of substantially the same size in cross-section as that of the annulus the velocity of rotation of the Water in the annulus, the conditions otherwise being the same, would be only about 21/2 feet per second. Accordingly by the invention it is rendered possible to remove heat from the surface exposed to the radiation in a combustion chamber or to other forrn of heat at a far greater ratey than would otherwise be feasible. If the same high speed were to be maintained with an ordi nary jacket, using the same quantity of water, the cooling passage would have to be reduced to= a width of about one-sixteenth of an inch. Passages as small as this would be difficult to make and it could not be guaranteed that there would be even flow and Vcooling over the whole surface.

A further advantage of the cooling jacket according to the invention is that the relatively large section annulus is readily cleaned and that there is a substantially equal cooling effect over different parts of the cooling surface.

The invention is illustrated by way of example in the accompanying drawings, in which Figure 1 shows in sectional elevation, partly broken away, the head of a combustion chamber provided with the cooling jacket of the present invention, Whilst Figure 2 is a plan view of the structure of Figure 1, partly sectional on the line 2 2 in the latter figure.

Referring to the drawings, I indicates the head of the shell of a combustion chamber and 2 indicates a refractory lining Within the combustion chamber shell.

To the shell I is fixed heat-producing means constituted by a fuel burner and its associated inlet ducts. The burner comprises a central spray nozzle 3 into which liquid fuel is fed tangentially at 4 to produce a vortex. The fuel inlet to the nozzle is from a duct 5 and the outlet into the combustion chamber is through the opening 6.

Surrounding the nozzle 3 is an outer member 1 which leaves an annular passage 8 for the introduction of liquid oxidant between the member 1 and the nozzle 3.

Fitted within the combustion chamber and surrounding the space in front of the nozzle is an annular cooling jacket 9 which is of substantially triangular cross-section, the wall l of which exposes to the combustion space a cooling surface in the shape of a frustum of a cone.

In the angle formed between the inner and outer walls I0 and Il of the cooling jacket, i. e. behind the wider part of the cone of the Cooling surface I0, is a tangential inlet l2 for introducing a coolant into the cooling jacket, which inlet is provided with a constriction I3. Two rings of orifices I4 in the inner wall of the cooling jacket close to the nozzle 3 provide an outlet for the coolant into the combustion space.

It will be appreciated that with a cooling jacket of this construction the coolant may be admitted at high Velocity through the tangential constricted inlet so that the body of coolant in the annular jacket is rotated at high speed, whilst the amount of coolant admitted, and discharged, is small, having regard to the cooling effect which the coolant exercises across the cooling surface I0 by reason of its rapid sweeping over the inside of that surface.

I claim:

In combination with heat-producing means, a cooling jacket arranged to expose a rapidly cooled 4 wall surface of which at least a part is substantially in the form of a frustum of a cone surrounding a zone in the vicinity of said heat-producing means, the said cooling jacket having an inlet tangentially disposed adjacent the part of the conical surface of greatest radius for admitting a cooling liquid at high velocity into said annular passage and having a cross-sectional area small in relation to the cross-sectional area of said annular passage, and at least one outlet from the part of the cooling jacket nearest to the heat-producing means for discharging the cooling liquid into said zone.

GEOFFREY JOSEPH GOLLIN.

REFERENCE S CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,531,475 Brandt Mar. 31, 1925 1,682,437 Sprado Aug. 28, 1928 1,812,339 Horne et al June 30, 1931 2,000,979 Parkhill et al May 14, 1935 2,097,104 Saha Oct. 26, 1937 FOREIGN PATENTS Number Country Date 14,641 Great Britain July 15, 1905 127,287 Germany Jan. 9, 1902 

